This invention relates to crew masks to be used in large aircraft for crew safety in the event of decompression of the cabin. More particularly, the invention relates to the inflatable harness used to secure such a mask in place for use.
A commonly used type of crew mask includes an inflatable head harness with inflatable elastic tubes that are inflated prior to placement of the harness over the head of the user and that are then deflated to grip the user's head. A valve is connected to the tubes to control inflation by the pressurized oxygen supply of a regulator on the respiratory mask.
Another similar type of oxygen supply system includes an oxygen supply with a face mask and an inflatable head harness. A plurality of chemical oxygen generators provide pressurized oxygen to a reservoir to inflate the pneumatic head harness and provide an initial breathing supply during the startup of the chemical oxygen generators.
Aircraft crew masks with inflatable harnesses are currently limited to designs that use high pressure oxygen and regulators mounted at the mask. The high pressure oxygen supply for the regulator is also used for inflating the harness. However, longstanding designs for military oxygen masks have mounted the high pressure oxygen supply and the oxygen regulator in the aircraft panel, providing lower pressure breathable oxygen to the masks, so that no high pressure oxygen gas is available at the mask to inflate a harness. Current military masks are limited to older “hard” head harnesses requiring adjustment to fit, or are supported by a flight helmet. Inflatable harness masks are preferred because they fit a range of personnel head sizes without requiring pre-adjustment or custom sized designs required of the older hard head harnesses. Thus, it would be desirable to provide an inflatable harness crew mask adapted to allow rapid inflation of the harness, to allow adaptation of the older style military mask designs to gain the benefit of automatic adjustability of modern inflatable harnesses. The current invention solves these and other problems.